" Dieselgate fed into a 180-degree turn in thinking that was in process about diesel fuel and urban transportation in Europe, where diesel cars have been popular. But anti-diesel sentiment was a big threat to Germany’s auto industry, which looms large in the country’s economy. German chancellor Angela Merkel decried the “demonizing” of diesel cars. Diesel, she said, was essential for combating climate change, owing to its lower CO2 emissions and greater fuel efficiency. She convened “diesel summits” to try to head off urban bans on diesel cars. But it was all to little avail. European cities, concerned about the higher levels of nitrogen oxide emissions from diesel, began to introduce limits for diesels. The aim for many is an eventual ban. "

― Daniel Yergin , The New Map: Energy, Climate, and the Clash of Nations